Combine the salt, sugar, and curing salt and divide it into two equal parts.
Combine the juniper berries, pepper, thyme, and rosemary.
Clean the meat with a cloth. Rub the meat with the first half of the curing mixture. Cure in the refrigerator for 10 days, removing any liquid that accumulates. Rub the meat clean and dry again with a cloth. Rub the meat with the second half of the curing mixture. Allow the meat to cure for 10 more days, removing any liquid that accumulates.Dry the meat with a cloth. Rub the meat with sea salt. Cure for 5 more days.Rub the loin with the dry spice mix. Pack the loin into a beef bung, slip the netting over it, and make a loop for hanging it. Poke holes in the casing to allow moisture to escape. Hang the meat in a temperature and humidity-controlled room of 55°F to 65° F with a relative humidity of up to 70%. Hang until 30% of the raw weight is lost. Cut into the thickest part of the meat to check for dryness. Store at 39°F or less until consumed.